• COMA: cache-only memory architecture
– Data migrates into local DRAM of CPUs where it
is being used
– Handles very large working sets cleanly
– Replacement from DRAM is messy: have to make
sure someone still has a copy
– Scope for interesting OS/architecture hybrid
– System slows down if total memory requirement
approaches RAM available, since space for
replication is reduced
• Examples: DDM, KSR-1/2, rumours from
IBM…